dsh-plugin-mermaid-gb-svg

A DeepSeek Harness plugin that turns Mermaid flowcharts into GB/T 1526-1989 compliant SVG (the Chinese national standard, identical to ISO 5807:1985), and exposes it to the model as one tool.

Preview

GB/T 1526-1989 symbol chart	Generated flowchart

Both SVGs are produced by this tool — the source .mmd files are in examples/.

Install

# 1) install into a profile (web shown here)
dsh plugin --profile web add dsh-plugin-mermaid-gb-svg

# 2) make the loader load it — append to $DSH_HOME/profiles/web/cordis.patch.yml

- insert:
    - id: mermaid-gb-svg
      name: dsh-plugin-mermaid-gb-svg
      # config:
      #   fontSize: 14
      #   paper: none

For local development point at the source directory instead: dsh plugin --profile web add /path/to/dsh-plugin-mermaid-gb-svg.

Tool: `mermaid_to_gb_svg`

Parameter	Type	Description
`out`	string, required	Output path. Ending in `.svg` = file name (multi-diagram gets `-1/-2`), otherwise output dir/prefix
`source`	string	Mermaid source (mutually exclusive with `path`)
`path`	string	Input `.mmd`/`.mermaid`, or `.md` containing ```mermaid blocks (all blocks extracted; nearest heading above becomes the caption)
`title`	string	Figure caption
`dir`	`td`\|`lr`\|`bt`\|`rl`	Force flow direction
`paper`	`none`\|`auto`\|`a4`\|`a4l`\|`a3`\|`a3l`	Sheet size; `none` (default) emits one large SVG, others paginate when the drawing does not fit
`font_size`	integer	Body font size in px (14 ≈ 10.5pt)
`font_tu`	boolean	Use technical-drawing font (GB/T 14691 FangSong)
`caption`	boolean	Draw the caption (default true)

Returns files, diagrams, pages, summary, warnings.

GB/T 1526-1989 symbols

Symbol	Meaning	Mermaid syntax
rounded rectangle	terminal (start/end)	`A([x])` `A((x))` `A(x)`
rectangle	process	`A[x]`
diamond	decision	`A{x}`
parallelogram	data (input/output)	`A[/x/]` `A[\x\]`
hexagon	preparation	`A{{x}}`
double-sided rectangle	predefined process	`A[[x]]`
cylinder	direct access storage	`A[(x)]`
trapezoid	manual operation	`A{/x/}`
sloped-top quad	manual input	`A{\x\}`
square bracket	annotation	`A>x]`
circle	connector (on page)	`A@{ shape: connector, label: "A" }`
pentagon	off-page connector	`A@{ shape: off-page, label: "B" }`
—	document / multi-document	`A@{ shape: doc, label: "report" }` / `docs`
—	display / delay	`A@{ shape: display, label: "display" }` / `delay`
—	internal storage	`A@{ shape: internal-storage, label: "storage" }`

shape accepts both Mermaid v11 names and Chinese names (处理/起止/判断/数据/准备/预定义处理/ 直接存取存储/人工输入/人工操作/文档/多文档/显示/延迟/内部存储/注释/连接符/换页连接符).

Drawing conventions

Flow runs left-to-right or top-to-bottom; flowlines are orthogonal with solid arrowheads.
Decision branches: 是 leaves the bottom vertex downward, 否 leaves the right vertex (going right first, then turning).
Every incoming flowline enters a symbol vertically at its top centre.
At most 3 bends per flowline — routes are tried in order 0→1→2→3 bends and the first one that does not cross a symbol wins.
Geometry is self-checked after generation (overlaps, flowlines through symbols) and reported in warnings.

Pagination (optional)

With paper: a4 (or a3/auto), a drawing that does not fit is split:

cuts fall in the gaps between layers (and between columns of symbols), never through a symbol;
each sheet is sized in real millimetres (width="210mm" height="297mm") with a frame, a binding margin and a (page n/N) caption;
each broken flowline gets an off-page connector (pentagon) pointing along the flow, and the connector sits at the same place with the same label on both sheets.

Configuration

Key	Default	Meaning
`font`	`SimSun, '宋体', 'Microsoft YaHei', sans-serif`	Font family
`fontSize`	`14`	Body font size (px)
`stroke`	`1.6`	Line width
`paper`	`none`	Default sheet size

Sandbox

Writes go through the Harness ctx.fs seam with the session's sandbox policy, and support the same one-shot sandbox_permissions + justification escalation retry as the built-in write tool.

Development

npm test        # test/engine.test.mjs + test/plugin.test.mjs

lib/engine.js is generated from the CLI version (tools/mermaid2gb-svg.js) so both stay in sync; edit the CLI and regenerate rather than editing the engine directly.

Feedback

Feedback is what decides what gets built next — especially standard-compliance corrections, since GB/T 1526-1989 has details that are easy to get subtly wrong.

Channel	Use it for
Issues	Bugs, symbol corrections (there is a dedicated template — please cite the clause/figure), feature requests
Discussions	Usage questions, layout/typography opinions, open-ended ideas
sandyyst@hotmail.com	Anything you would rather not post publicly

When reporting a problem, attach the Mermaid source. A one-line description plus the .mmd is usually enough to reproduce it — the generated diagram, the tool's warnings array, and your plugin version help too.

If the tool reports geometry warnings, the output already carries the link to the issue tracker — that is the moment the report is most useful.

License

MIT

dsh-plugin-mermaid-gb-svg

Install

README